Imprinting methods are known which obtain a microstructure with micro protrusions by press-forming a resin, such as polystyrene, with a mold having a microstructure and then remove a formed product from the mold (for example, refer to Japanese Unexamined Patent Publication TOKKAI No. 2005-189128). FIG. 10 schematically shows a main part of an imprinting device in a prior art.
An imprinting device in a prior art, shown in FIG. 10, drives a pressing mechanical section 102 with a ball screw by a servomotor 101 to move a mold 103 fixed at the bottom edge downward, and presses the mold against a forming material 104 of a resin. A force sensor 106 is provided between a holding section 105 that holds the forming material 104 and a holding table 107. The force sensor 106 measures the pressing force, and a controller 109 controls the pressing force thorough servo control of the servomotor 101, based on a measurement signal amplified by an amplifier 108. After pressing, the controller 109 reverse-rotates the servo motor 101 to drive the pressing mechanism 102 so that the mold 103 moves upward for mold-releasing, and thus the mold 103 and forming material 104 are separated from each other.
In an imprinting device, as described above, although it is desirable to separate the mold 103 and the forming material 104 slowly for mold-releasing from a viewpoint of preventing generation of defects, the mold 103 is moved at a relatively high speed in consideration of productivity. Therefore, the pitch of the ball screw of the pressing mechanism 102 is designed to be large and the resolution angle of the servo motor 101 is designed to be large. That is, for the pressing mechanism 102, the minimum moving distance (unit) ΔZ is large, and the variation in force ΔF corresponding to ΔZ becomes large, ΔF being not smaller than 10 Newton, for example. Accordingly, an imprinting device in a prior art is incapable of slowly separating the mold 103 and forming material 104 from each other for mold-releasing, which tends to easily cause defects. On the other hand, with a shorter pitch of the ball screw of the pressing mechanism 102 and a smaller resolution angle of the servo motor 101, the time required for pressing becomes longer, lowering the productivity of the imprinting device.
To solve problems, as described above, with prior arts, an object of the present invention is to provide an imprinting apparatus and method which enable mold-releasing operation that minimizes generation of defects, while maintaining the productivity.